Mitsumi Electric Company Ltd.

Ryota Kageyama

Takashi Takeda

Takeshi Yamaguchi

Norihito Kawaguchi

Takatoshi Itagaki

Nobuhito Tanaka

Koji Koshimizu

Yoshihiro Satake

Tsutomu Yamauchi

Koichi Murano

Koji Yano

Junji Takeshita

A battery protection circuit for protecting a secondary battery, the battery protection circuit not having a CPU, includes a non-volatile memory into which characteristics data determining protective characteristics of the battery protection circuit are writable; and a protection operation circuit which performs a protection operation of the secondary battery based on the characteristics data read out of the non-volatile memory.

Battery protection circuit, battery protection apparatus, and battery pack

A secondary battery protection circuit for protecting a secondary battery including: a power supply terminal; a protection operation circuit configured to monitor a state of the secondary battery through the power supply terminal to generate a signal for turning on/off conduction of a current path between the secondary battery and a load according to a protection state determined by the monitored state of the secondary battery; a nonvolatile memory in which data is written by a writing voltage being provided at the power supply terminal, an operation of the secondary battery protection circuit being controlled by the data; a voltage generation circuit configured to generate a provision voltage which is provided to a low withstand voltage circuit; and a control circuit configured to enable the nonvolatile memory to store the data therein in accordance with the protection state upon an input voltage being greater than a determination threshold voltage.

Secondary battery protection circuit, secondary battery protection device, battery pack and method of writing data

A battery protection IC has detection circuits to detect faults of an overcharge, an over-discharge, and an overcurrent of a secondary battery; a control circuit to protect the secondary battery, by controlling (dis)charging the secondary battery upon the fault; and a delay circuit to generate delay after the fault before the controlling. The IC includes a memory unit to store data for setting and adjusting a circuit characteristic of the IC; and a setting circuit to set and adjust the circuit characteristic, based on the data from the memory unit. The memory unit includes a pair of non-volatile memory cells to complementarily store one bit, and a latch circuit directly cross-coupled with the memory cells, for each bit of the data. The latch circuit statically outputs the data from the memory cells to the setting circuit when the IC is turned on.

Battery protection integrated circuit and circuit characteristic setting method

There is provided a method of correcting an overcurrent detection voltage of a battery protection integrated circuit including a current path between a first terminal and a second terminal, one or more transistors for controlling current of a secondary battery, an overcurrent detection circuit and a control circuit. The method comprises the steps of: measuring a resistance value between the first terminal and the second terminal wherein the one or more transistors are turned on at a predetermined temperature; estimating resistance values between the first terminal and the second terminal at respective temperatures based on the measured resistance value; calculating adjusting data for canceling temperature dependency of charge or discharge current of the secondary battery based on the measured resistance value and the estimated resistance values, wherein a value of the charge or discharge current varies depending on temperature; correcting the overcurrent detection voltage based on the calculated adjusting data.

Method of overcurrent detection voltage correction and battery protection integrated circuit

Growing community of inventors

Tokyo, Japan

Ryota Kageyama